Originally Posted by lucid
I am not aware of a DIY, but check the E90 DIY page. They might have some. You'd have to remove the carrier, and the rest should be fairly straight forward. You do need to raise the car high to be able to comfortablely remove the larger nuts holding the carrier in place though.
A few short cracks is OK. I would keep an eye on them. When they spread around and you can easily catch them with your finger, it's time to replace them.
Thank you as always.
I am attaching a pic of the cracks. They are not deep and I cannot feel a difference in the disc surface with my finger. Rotor depth seems to be ok, a lip is developing but not very deep yet though I have no way to measure exactly.
Having said that, I have had this rotors on the car since new and it has done 6 track days (1 street tires, 5 R-comps) of about 100-140 miles each (on HT-10s first then Pagids) and 6,000 street miles (on stock pads). I am pleasantly surprised at rotor/pad durability so far.
These pics are of my front rotors. I only use track pads on the front, I have found that the rears hold up fine with stock pads and I don't really feel any balance issues.